Safety Sean Davis has agreed to a one-year deal worth up to $5 million with Washington, according to his agent, Drew Rosenhaus.
Davis, 26, spent the past four seasons with the Steelers.
Pittsburgh made him a second-round choice in 2016.
He played 48 games with 41 starts in his time in Pittsburgh, making 247 tackles, 2.5 sacks, five interceptions and 20 pass breakups.
He and Landon Collins should form one of the top safety tandems in the league.